Field of the Invention
The present invention relates to a robot cleaner, and more particularly to a robot cleaner that is capable of passing an obstacle.
Discussion of the Related Art
In general, a vacuum cleaner is an apparatus that suctions air containing foreign matter, such as dust, from the outside using an air suction device provided in a cleaner body of the vacuum cleaner to generate air suction force and then separates the foreign matter from the air to collect foreign matter.
The vacuum cleaner performing the above functions may be classified as a manual vacuum cleaner that is directly manipulated by a user or a robot cleaner that performs automatic cleaning without user manipulation.
Specifically, the robot cleaner is an apparatus that travels within a region to be cleaned to suction foreign matter, such as dust, from a floor. In other words, the robot cleaner automatically performs cleaning within a predetermined region. To this end, the robot cleaner includes a distance sensor to sense the distance from the robot cleaner to obstacles, such as furniture, office supplies, and walls, located within a region to be cleaned, and left and right wheels to move the robot cleaner. The left and right wheels are configured to be rotated by a left wheel motor and a right wheel motor, respectively. As the left wheel motor and the right wheel motor are rotated, the robot cleaner performs indoor cleaning while changing travel directions.
In addition, a suction nozzle to suction foreign matter from the floor is provided at the lower part of the robot cleaner. The suction nozzle includes a nozzle case unmovably fixed to the cleaner body of the robot cleaner, a suction port formed at the bottom of the nozzle case to suction foreign matter, and an agitator rotatably provided in the suction port to sweep foreign matter, such as dust, on the floor into the suction part.
Meanwhile, the robot cleaner further includes a caster configured to smoothly turn the robot cleaner in addition to the left and right wheel motor, which are electrically powered.
The conventional robot cleaner with the above-stated construction may not pass a door sill or obstacle having a narrow width.
Korean Patent Application Publication No. 10-2013-0035389 discloses a structure in which an auxiliary wheel and a main wheel are connected to each other via a rotary shaft in a state in which a gear assembly is disposed between the auxiliary wheel and the main wheel. In this disclosure, however, the obstacle may be caught in a gap defined between the auxiliary wheel and the main wheel. In addition, it is necessary to extend a rotary shaft such that the auxiliary wheel and the main wheel are connected to each other via the rotary shaft. That is, the structure is complicated.